//program:求圆的面积和周长
//author:软件2204冯佳晨
//date;3/13/2023
#define PI 3.1415926
#include<iostream>
using namespace std;

//创建 圆类
class Circle
{
public:
	double r;

	double fs(double r)
	{
		return PI * pow(r, 2);;
	}

	double fc(double r)
	{
		return 2*PI*r;
	}
};


int main()
{
	Circle c1;//创建圆类的具体对象
	cin >> c1.r;
	cout << "S = " << c1.fs(c1.r) << endl;
    cout << "C = " << c1.fc(c1.r) << endl;
	return 0;
}